Risk factors for traumatic dental injuries in the primary dentition: concepts, interpretation, and evidence

The purpose of this comprehensive review is to explore the main concepts related to quantification and interpretation of risk factors and investigate characteristics associated with traumatic dental injuries (TDI) in the primary dentition. Initially, the main concepts related to causality and risk factors were summarized, including how to measure, express, and compare risk as well as interpret statistical significance. Based on a structured search through PubMed, original research articles regarding TDI and associated factors in the primary dentition were then reviewed by two examiners. Studies with a sample size of at least 300 children aged between 0 and 6 years were summarized according to journal, country, study design, and type of statistical analysis. Variables associated with TDI in primary teeth were identified from studies with multivariable analysis. Measures of effect size and P values were presented. Thirty-two studies were retrieved: most were cross-sectional in design and only 17 (53.1%) performed multivariable analysis. Most investigations did not find an association between gender and socioeconomic variables with TDI. Increased overjet was the only factor consistently identified as an associated factor. Behavioral characteristics have been recently investigated and suggested as potential risk factors for TDI in the primary dentition. In conclusion, increased overjet is undoubtedly associated with TDI in the primary dentition. As behavioral factors may be targeted by preventive strategies, their role on TDI occurrence should be clarified in future cohort studies. Clinicians should understand the terms and measures described in studies on risk factors to properly apply knowledge and benefit patients.